However, it contains the so-called "blank rune" or "rune of Wyrd" described by Blum. There is no evidence that this blank rune was actually used in any form of runic divination. Instead it appears to be a modern invention by Ralph Blum. I would not use it in my own divinatory workings.

I have never purchased a set as I was required to make them. Perhaps you should make your own as well? Some of the materials specified as acceptable are available. The wood from a nut bearing tree for instance. Many people don't worry about any particular material other than what they are drawn to and I think that is fine. I do believe that when you make them for your own use, they work better. -Cheers!